Superheater and process of operating the same



c.- E. LUCKE SUPERHEATER AND PROCESS OF OPERATING THE SAME Filed May 15, 1928 Feb. 16, 1932.

' ATTORNEYS Patented Feb. 16, 1932 CHARLES E. LUCKE, OF NEW-YORK, N. Y., ASSIGNOR TO THE BABGOCK &'WILCOX COM- I OE IBAYQINNE, NEW JERSEY, A; CORPORATION svrm mam m S or ornaarrno E This invention relates to a steam boiler that is provided with two superheaters, one J of which may. be heated by radiant heat from theboiler furnace and the other is heated by description in connection with theaccompanying drawings in which Fig. 1 is a-vertical sectionvthrough an illustrative embodiment of the invention, and Fig. 2 is a section on an enlarged scale showing details of the regulator. In the drawings reference character 1 indicates the furnace of a boiler above which is illustrated a boiler of the Babcock & Wilcox type having the usual steam and water drum 2, and a bank of inclined tubes 3 connected to uptake headers 4 and downtake headers 5 in the usual way. Bafiies 6 direct the hot products of combustion from the furnace 1 a plurality of times over the bank of tubes 3 to the gas outlet 7.

' A superheater 8 is located above the bank of tubes 3 in such a postion as to be swept over by the gases after they have passed once across the bank of tubes 3. -It is to be understood that such a postion is often designated standard, and the word as used herein is intended to have this meaning. Another superheater 9 is located along the inside Wall of the furnace in such a position that it will be heated by radiant heat from the furnace. A pipe 10 connects the steam space of the steam and water drum 2 to a two-wa valve 11 that is shown in detail in Fig. 2. pipe 12 leads from one'of the outlets of the valve 11 to the superheater 8 from which a pipe 13 leads to the steam outlet pipe or steam main 14... A pipe 15 leads I from the other outlet of the valve .11 to the radiant heat from which a connection 15 extends to the steam mainjl. V Q

The valve 11 is provided with a regulator comprising an upper cylindrical memberi17 with a lower serrated end 18 and a lower cylindrical member .19prov'ided with an upper serrated end 20. The lowermember19 is closedv at the bottom as shownat 21. A rod 22 connects the cylindrical members 17 and 19 V by means, of spiders-.23. H The lower-end of the valve casing'merges into (male 24 ofithe U-tube 25 containinga liquid, sue as mercury, for example. The other'le .26 of the U-tube is'connected bymeans of t e pipe 27 to the steam outlet main. 14. h I. 5

The operation is as-follows: The valve 11 operates automatically. to divide the steam that passes through the super-heaters 8 and 9, .respectively,'in such a manner that larger proportions of steam pass through the s'uper- 7 heater 8 at higher ratings so that the mixed steam from the two superheaters will have the proper amount of superheat at difi'erent loads. It is well known that a characteristic of radiant heat superheaters is that they give a falling temperature curve with increasingloads and that a superheater located like the superheater 8 gives a rising temperature curve with increasing loads so that by increasing the proportion of steam that passes through the superheater 8 at increasing loads, the proper amount of superheat canbe maintained in the total steam passing from the boiler. It will be understood that the word characteristic applied to a superheater defines the natureof change of final temperature with respect to. increase of load. The pressure drops through the superheaters between the pipes 10 and 14 are, ofppurse, greater at high loads so that the mercury rises in the leg 26 of the U-tube 25 and that in .the leg 24 lowers when the load is increased,,thus causing the cylinders 18 and 19 to descend with the result that a larger proportion of the steam is permitted to pass 'throughthe outlet and pipe 12 into the superheater 8 and a smaller proportion passes through the outletand pipe 15 into the superheater 9.

The invention Is also applicable to supersuperheater 9 heaters, located at different? positions anyheated then the invention serves to protect it from overheating and burning quite 1nde-' pendent of the constancy of steam te'm erature. In connection with the inventlon erein disclosed, it is to be noted that subject which comprises passin matter not herein claimed is disclosed and claimed in my copending application Serial No. 575,604, filed November 17, 1931.

I claim:

1. The process of regulating the amount of superheat in steam passing from a boiler, which comprises passing a portion of the steamfrom the boiler through a radiantly heated superheater and another portion through a standard superheater, uniting the steam after it has passed through the superheaters, and controlling the relative amounts of steam that passes through the superheaters by thedifierence in pressures at the inlets and outlets of said superheaters so that a propertionately larger amount of steam passes through the standard superheater as the total is increased. o 2. The process of regulating the amount of superheat in steam passing from a boiler, which comprises superheating a part of the steam from the boiler by radiant heat from the boiler furnace and another part by hot gases from the furnace, uniting the parts and controlling the proportions of the two by the difference in pressures at the inlets and outlets of said superheaters so that a proportionately larger amount of steam is heated by hot gases from the furnace as the total is increased.

3. The process of regulating the amount of superheat in steam passing from a boiler, a portion ofthe steam from the boiler t rough a radiantly heated superheater and another portion through another superheater, uniting the steam after it has passed through the superheaters, and decreasing the proportionate amount that passes through the radiantly heated superheater when the total is increased.

4:. The process of regulating the amount of superheat insteam passing from a boiler, which comprises passing a portion of the steam through a superheater having a rising temperature curve and another portion through another superheater having a falling temperature curve with increasing loads,

uniting the steam after it has passed through said superheaters, and controlling the relative amounts of steam that pass through said superheaters by the diiierence in pressures at the inlets and outlets of said superheaters so that the proportionate amount of steam that passes through the superheater having a fallmg temperature curve decreases when the total is increased.

5. The process of regulating the amount of superheat in steam passing. from a boiler, which comprises passing a portion of the steam from the boiler through a radiantly heated superheater and another portion through another superheater, uniting the steam after it has passed through the superheaters, and decreasing the proportionate amount that passes through the radiantly heated superheater when the total is increased in such a manner that substantially constant steam temperature is maintained at different loads. 7

6. The process of regulating the amount of superheat in steam passing from a boiler, which comprises superheating a part of the steam from the boiler by radiant heat from the boiler furnace and another part by hot gases from the furnace, uniting the parts and controlling the proportions of the two by the difierence in pressures at the inlets and outlets of said superheaters in such a manner that. the metal of the radiantly heated superheater is prevented from being overheated by passing a relatively greater proportion of the steam through it at low loads. f

7 In a water tube steamboiler, two superheaters, one of saidsuperheaters com rising a single row,of tubes alon the boiler urnace and heated mainly by radiant heat, the other one comprising a multiplicity of tubes in parallel mainly screened from radiant heat byv tubes of said 'boiler and receivin heat of gases from said furnace after t ey have passed over tubes of said boiler, and means connected to the steam outlet to control the proportion of steam that passes through said superheaters, said means simultaneously increasing the amount of steam that passes through one superheater as it decreases the amount that passes through the other one, said means being arrange and adapted to start and stop said increase and decrease together.

8. In a water tube steam boiler, two superheaters, one of said superheaters comprising a single row of tubes along the boiler furnace and heated mainly by radiant heat, the other one comprising a multiplicity of tubes in parallel mainly screened from radiant heat by tubes of said boiler and receiving heat of gases from said furnace after they have passed over tubes of said boiler, and means connected to the steam outlet tocontrol the proportion of steam that passes through said superheaters, said means comprising two mechanically .and rigidly connected pressure actuated valves.

9. In a water tube steam boiler, two superheaters, one of said superheaters comprising a single row of tubes along the boiler furnace and heated mainly by radiant heat, the other one comprising a multiplicity of tubes in parallel mainly screened from radiant heat by tubes of said boiler and receiving 5 heat of gases from said furnace after they have passed over tubes of said boiler, and means connected to the steam outlet to control the proportion of steam that passes through said superheaters, said means comprising two 10 mechanically and rigidly actuated valves actuated by the difierence in pressures at the inlet and outlet ends of said superheaters and controlling passage of steam through both superheaters. 15 CHARLES E. LUCKE. 

